The OSI security architecture focuses on security attacks, mechanisms, and services. These can be defined briefly as follows:
(i) Security Attack: Information security breaches are actions that compromise an organization's information. The term "attack on system security" refers to an attack on the security of a program that derives from an intelligent threat, that is, an intelligent act that is a deliberate attempt to evade the security services of the program and violate its security policies.
(ii) Security Mechanism: It is a method that can be used to detect, prevent, or recover from a security breach.
(iii) Security Service: An information transfer or processing service that enhances an organization's security and the security of its data processing systems. Providing the services requires the use of one or more security mechanisms to counter security attacks.